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plotting a function with mesh

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Artur Walter
Artur Walter on 17 Oct 2019
Hallo
I want to plot a function with mesh and find it's minimum
clear; close; clc;
f = @(x)(x(1).^2 + x(2).^2);
N = 200;
x1 = 0:2/(N-1):2;
x2 = -2:4/(N-1):2;
[x1, x2]= meshgrid(x1, x2);
x3 = f(x1, x2);
mesh (x1, x2, x3)
z = fminsearch(g , [0.5, 0.5])
% or I tried
function z = f(x1, x2)
z = x1.^2 + x2.^2;
end
function z = g(x)
z = x(1).^2 + x(2).^2;
end
Everthing failed!
How can I do it?

  2 Comments

Adam Danz
Adam Danz on 17 Oct 2019
"Everthing failed!"
This doesn't tell us what the problem is. If you're getting an error message, provide the entire copy-pasted message. If you're not getting an error but the plot isn't as expected, provide more detail about that.
Adam Danz
Adam Danz on 17 Oct 2019
For starters, you've got a local function named f and an anonymous function named f. You can't have both in the same script.

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Answers (1)

Swastik Sanjay Chaudhury
Swastik Sanjay Chaudhury on 4 Dec 2019
Hello Artur, I agree with the comment as mentioned by Adam Danz. A basic modification maked the code work without any problem.
clear; close; clc;
t = @(x)(x(1).^2 + x(2).^2);
N = 200;
x1 = 0:2/(N-1):2;
x2 = -2:4/(N-1):2;
[x1, x2]= meshgrid(x1, x2);
x3 = f(x1, x2);
mesh (x1, x2, x3)
z = fminsearch(t , [0.5, 0.5])
% or I tried
function z = f(x1, x2)
z = x1.^2 + x2.^2;
end

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